cregit-Linux how code gets into the kernel

Release 4.9 drivers/usb/misc/usblcd.c

Directory: drivers/usb/misc
/*****************************************************************************
 *                          USBLCD Kernel Driver                             *
 *                            Version 1.05                                   *
 *             (C) 2005 Georges Toth <g.toth@e-biz.lu>                       *
 *                                                                           *
 *     This file is licensed under the GPL. See COPYING in the package.      *
 * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com)        *
 *                                                                           *
 *                                                                           *
 * 28.02.05 Complete rewrite of the original usblcd.c driver,                *
 *          based on usb_skeleton.c.                                         *
 *          This new driver allows more than one USB-LCD to be connected     *
 *          and controlled, at once                                          *
 *****************************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>


#define DRIVER_VERSION "USBLCD Driver Version 1.05"


#define USBLCD_MINOR		144


#define IOCTL_GET_HARD_VERSION	1

#define IOCTL_GET_DRV_VERSION	2


static DEFINE_MUTEX(lcd_mutex);

static const struct usb_device_id id_table[] = {
	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);

static DEFINE_MUTEX(open_disc_mutex);



struct usb_lcd {
	
struct usb_device	*udev;			/* init: probe_lcd */
	
struct usb_interface	*interface;		/* the interface for
                                                           this device */
	
unsigned char		*bulk_in_buffer;	/* the buffer to receive
                                                           data */
	
size_t			bulk_in_size;		/* the size of the
                                                           receive buffer */
	
__u8			bulk_in_endpointAddr;	/* the address of the
                                                           bulk in endpoint */
	
__u8			bulk_out_endpointAddr;	/* the address of the
                                                           bulk out endpoint */
	
struct kref		kref;
	
struct semaphore	limit_sem;		/* to stop writes at
                                                           full throttle from
                                                           using up all RAM */
	
struct usb_anchor	submitted;		/* URBs to wait for
                                                           before suspend */
};

#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)


#define USB_LCD_CONCURRENT_WRITES	5


static struct usb_driver lcd_driver;





static void lcd_delete(struct kref *kref)
{
	struct usb_lcd *dev = to_lcd_dev(kref);

	usb_put_dev(dev->udev);
	kfree(dev->bulk_in_buffer);
	kfree(dev);
}



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georges tothgeorges toth40100.00%1100.00%


Total40100.00%1100.00%






static int lcd_open(struct inode *inode, struct file *file)
{
	struct usb_lcd *dev;
	struct usb_interface *interface;
	int subminor, r;

	mutex_lock(&lcd_mutex);
	subminor = iminor(inode);

	interface = usb_find_interface(&lcd_driver, subminor);
	if (!interface) {
		mutex_unlock(&lcd_mutex);
		printk(KERN_ERR "USBLCD: %s - error, can't find device for minor %d\n",
		       __func__, subminor);
		return -ENODEV;
	}

	mutex_lock(&open_disc_mutex);
	dev = usb_get_intfdata(interface);
	if (!dev) {
		mutex_unlock(&open_disc_mutex);
		mutex_unlock(&lcd_mutex);
		return -ENODEV;
	}

	/* increment our usage count for the device */
	kref_get(&dev->kref);
	mutex_unlock(&open_disc_mutex);

	/* grab a power reference */
	r = usb_autopm_get_interface(interface);
	if (r < 0) {
		kref_put(&dev->kref, lcd_delete);
		mutex_unlock(&lcd_mutex);
		return r;
	}

	/* save our object in the file's private structure */
	file->private_data = dev;
	mutex_unlock(&lcd_mutex);

	return 0;
}


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georges tothgeorges toth6133.33%111.11%


oliver neukumoliver neukum5630.60%333.33%


greg kroah-hartmangreg kroah-hartman3519.13%222.22%


arnd bergmannarnd bergmann2513.66%111.11%


alan sternalan stern52.73%111.11%


harvey harrisonharvey harrison10.55%111.11%


Total183100.00%9100.00%






static int lcd_release(struct inode *inode, struct file *file)
{
	struct usb_lcd *dev;

	dev = file->private_data;
	if (dev == NULL)
		return -ENODEV;

	/* decrement the count on our device */
	usb_autopm_put_interface(dev->interface);
	kref_put(&dev->kref, lcd_delete);
	return 0;
}


Contributors
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greg kroah-hartmangreg kroah-hartman2644.83%133.33%


georges tothgeorges toth2543.10%133.33%


oliver neukumoliver neukum712.07%133.33%


Total58100.00%3100.00%






static ssize_t lcd_read(struct file *file, char __user * buffer,
			size_t count, loff_t *ppos)
{
	struct usb_lcd *dev;
	int retval = 0;
	int bytes_read;

	dev = file->private_data;

	/* do a blocking bulk read to get data from the device */
	retval = usb_bulk_msg(dev->udev,
			      usb_rcvbulkpipe(dev->udev,
					      dev->bulk_in_endpointAddr),
			      dev->bulk_in_buffer,
			      min(dev->bulk_in_size, count),
			      &bytes_read, 10000);

	/* if the read was successful, copy the data to userspace */
	if (!retval) {
		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
			retval = -EFAULT;
		else
			retval = bytes_read;
	}

	return retval;
}


Contributors
PersonTokensPropCommitsCommitProp
georges tothgeorges toth9481.74%133.33%


greg kroah-hartmangreg kroah-hartman1513.04%133.33%


al viroal viro65.22%133.33%


Total115100.00%3100.00%






static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usb_lcd *dev;
	u16 bcdDevice;
	char buf[30];

	dev = file->private_data;
	if (dev == NULL)
		return -ENODEV;

	switch (cmd) {
	case IOCTL_GET_HARD_VERSION:
		mutex_lock(&lcd_mutex);
		bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
		sprintf(buf, "%1d%1d.%1d%1d",
			(bcdDevice & 0xF000)>>12,
			(bcdDevice & 0xF00)>>8,
			(bcdDevice & 0xF0)>>4,
			(bcdDevice & 0xF));
		mutex_unlock(&lcd_mutex);
		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
			return -EFAULT;
		break;
	case IOCTL_GET_DRV_VERSION:
		sprintf(buf, DRIVER_VERSION);
		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
			return -EFAULT;
		break;
	default:
		return -ENOTTY;
		break;
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
greg kroah-hartmangreg kroah-hartman13569.95%342.86%


georges tothgeorges toth4422.80%114.29%


arnd bergmannarnd bergmann105.18%114.29%


alan coxalan cox31.55%114.29%


oliver neukumoliver neukum10.52%114.29%


Total193100.00%7100.00%






static void lcd_write_bulk_callback(struct urb *urb)
{
	struct usb_lcd *dev;
	int status = urb->status;

	dev = urb->context;

	/* sync/async unlink faults aren't errors */
	if (status &&
	    !(status == -ENOENT ||
	      status == -ECONNRESET ||
	      status == -ESHUTDOWN)) {
		dev_dbg(&dev->interface->dev,
			"nonzero write bulk status received: %d\n", status);
	}

	/* free up our allocated buffer */
	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
			  urb->transfer_buffer, urb->transfer_dma);
	up(&dev->limit_sem);
}


Contributors
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greg kroah-hartmangreg kroah-hartman4850.00%350.00%


georges tothgeorges toth3940.62%116.67%


oliver neukumoliver neukum88.33%116.67%


daniel mackdaniel mack11.04%116.67%


Total96100.00%6100.00%






static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
			 size_t count, loff_t *ppos)
{
	struct usb_lcd *dev;
	int retval = 0, r;
	struct urb *urb = NULL;
	char *buf = NULL;

	dev = file->private_data;

	/* verify that we actually have some data to write */
	if (count == 0)
		goto exit;

	r = down_interruptible(&dev->limit_sem);
	if (r < 0)
		return -EINTR;

	/* create a urb, and a buffer for it, and copy the data to the urb */
	urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!urb) {
		retval = -ENOMEM;
		goto err_no_buf;
	}

	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
				 &urb->transfer_dma);
	if (!buf) {
		retval = -ENOMEM;
		goto error;
	}

	if (copy_from_user(buf, user_buffer, count)) {
		retval = -EFAULT;
		goto error;
	}

	/* initialize the urb properly */
	usb_fill_bulk_urb(urb, dev->udev,
			  usb_sndbulkpipe(dev->udev,
			  dev->bulk_out_endpointAddr),
			  buf, count, lcd_write_bulk_callback, dev);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	usb_anchor_urb(urb, &dev->submitted);

	/* send the data out the bulk port */
	retval = usb_submit_urb(urb, GFP_KERNEL);
	if (retval) {
		dev_err(&dev->udev->dev,
			"%s - failed submitting write urb, error %d\n",
			__func__, retval);
		goto error_unanchor;
	}

	/* release our reference to this urb,
           the USB core will eventually free it entirely */
	usb_free_urb(urb);

exit:
	return count;
error_unanchor:
	usb_unanchor_urb(urb);
error:
	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
	usb_free_urb(urb);
err_no_buf:
	up(&dev->limit_sem);
	return retval;
}


Contributors
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georges tothgeorges toth13846.46%111.11%


greg kroah-hartmangreg kroah-hartman9732.66%333.33%


oliver neukumoliver neukum5819.53%222.22%


daniel mackdaniel mack20.67%111.11%


harvey harrisonharvey harrison10.34%111.11%


zack parsonszack parsons10.34%111.11%


Total297100.00%9100.00%




static const struct file_operations lcd_fops = {
	.owner =        THIS_MODULE,
	.read =         lcd_read,
	.write =        lcd_write,
	.open =         lcd_open,
	.unlocked_ioctl = lcd_ioctl,
	.release =      lcd_release,
	.llseek =	 noop_llseek,
};

/*
 * usb class driver info in order to get a minor number from the usb core,
 * and to have the device registered with the driver core
 */

static struct usb_class_driver lcd_class = {
	.name =         "lcd%d",
	.fops =         &lcd_fops,
	.minor_base =   USBLCD_MINOR,
};




static int lcd_probe(struct usb_interface *interface,
		     const struct usb_device_id *id)
{
	struct usb_lcd *dev = NULL;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	size_t buffer_size;
	int i;
	int retval = -ENOMEM;

	/* allocate memory for our device state and initialize it */
	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		goto error;
	kref_init(&dev->kref);
	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
	init_usb_anchor(&dev->submitted);

	dev->udev = usb_get_dev(interface_to_usbdev(interface));
	dev->interface = interface;

	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
		dev_warn(&interface->dev, "USBLCD model not supported.\n");
		retval = -ENODEV;
		goto error;
	}

	/* set up the endpoint information */
	/* use only the first bulk-in and bulk-out endpoints */
	iface_desc = interface->cur_altsetting;
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (!dev->bulk_in_endpointAddr &&
		    usb_endpoint_is_bulk_in(endpoint)) {
			/* we found a bulk in endpoint */
			buffer_size = usb_endpoint_maxp(endpoint);
			dev->bulk_in_size = buffer_size;
			dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
			dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
			if (!dev->bulk_in_buffer)
				goto error;
		}

		if (!dev->bulk_out_endpointAddr &&
		    usb_endpoint_is_bulk_out(endpoint)) {
			/* we found a bulk out endpoint */
			dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
		}
	}
	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
		dev_err(&interface->dev,
			"Could not find both bulk-in and bulk-out endpoints\n");
		goto error;
	}

	/* save our data pointer in this interface device */
	usb_set_intfdata(interface, dev);

	/* we can register the device now, as it is ready */
	retval = usb_register_dev(interface, &lcd_class);
	if (retval) {
		/* something prevented us from registering this driver */
		dev_err(&interface->dev,
			"Not able to get a minor for this device.\n");
		usb_set_intfdata(interface, NULL);
		goto error;
	}

	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);

	dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
		 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
		 (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);

	/* let the user know what node this device is now attached to */
	dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
		 interface->minor);
	return 0;

error:
	if (dev)
		kref_put(&dev->kref, lcd_delete);
	return retval;
}


Contributors
PersonTokensPropCommitsCommitProp
georges tothgeorges toth25357.89%16.67%


greg kroah-hartmangreg kroah-hartman14633.41%640.00%


oliver neukumoliver neukum235.26%320.00%


luiz fernando capitulinoluiz fernando capitulino61.37%16.67%


jiri slabyjiri slaby61.37%16.67%


wolfram sangwolfram sang10.23%16.67%


eric sesterhenneric sesterhenn10.23%16.67%


kuninori morimotokuninori morimoto10.23%16.67%


Total437100.00%15100.00%






static void lcd_draw_down(struct usb_lcd *dev)
{
	int time;

	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
	if (!time)
		usb_kill_anchored_urbs(&dev->submitted);
}


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Total39100.00%1100.00%






static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct usb_lcd *dev = usb_get_intfdata(intf);

	if (!dev)
		return 0;
	lcd_draw_down(dev);
	return 0;
}


Contributors
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oliver neukumoliver neukum40100.00%1100.00%


Total40100.00%1100.00%






static int lcd_resume(struct usb_interface *intf)
{
	return 0;
}


Contributors
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oliver neukumoliver neukum14100.00%1100.00%


Total14100.00%1100.00%






static void lcd_disconnect(struct usb_interface *interface)
{
	struct usb_lcd *dev;
	int minor = interface->minor;

	mutex_lock(&open_disc_mutex);
	dev = usb_get_intfdata(interface);
	usb_set_intfdata(interface, NULL);
	mutex_unlock(&open_disc_mutex);

	/* give back our minor */
	usb_deregister_dev(interface, &lcd_class);

	/* decrement our usage count */
	kref_put(&dev->kref, lcd_delete);

	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
}


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greg kroah-hartmangreg kroah-hartman4150.62%571.43%


georges tothgeorges toth2834.57%114.29%


oliver neukumoliver neukum1214.81%114.29%


Total81100.00%7100.00%




static struct usb_driver lcd_driver = {
	.name =		"usblcd",
	.probe =	lcd_probe,
	.disconnect =	lcd_disconnect,
	.suspend =	lcd_suspend,
	.resume =	lcd_resume,
	.id_table =	id_table,
	.supports_autosuspend = 1,
};


module_usb_driver(lcd_driver);

MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");

MODULE_DESCRIPTION(DRIVER_VERSION);
MODULE_LICENSE("GPL");

Overall Contributors
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georges tothgeorges toth79342.47%12.78%


greg kroah-hartmangreg kroah-hartman68836.85%1438.89%


oliver neukumoliver neukum29415.75%616.67%


arnd bergmannarnd bergmann462.46%25.56%


zack parsonszack parsons90.48%12.78%


luiz fernando capitulinoluiz fernando capitulino70.37%25.56%


al viroal viro60.32%12.78%


jiri slabyjiri slaby60.32%12.78%


alan sternalan stern50.27%12.78%


alan coxalan cox40.21%12.78%


daniel mackdaniel mack30.16%12.78%


harvey harrisonharvey harrison20.11%12.78%


kuninori morimotokuninori morimoto10.05%12.78%


marton nemethmarton nemeth10.05%12.78%


wolfram sangwolfram sang10.05%12.78%


eric sesterhenneric sesterhenn10.05%12.78%


arnaldo carvalho de meloarnaldo carvalho de melo0.00%00.00%


Total1867100.00%36100.00%

  
Directory: drivers/usb/misc